diff --git a/server/package.json b/server/package.json
index e68ae1703..dd5625f35 100644
--- a/server/package.json
+++ b/server/package.json
@@ -20,6 +20,7 @@
     "agenda": "^3.1.0",
     "agendash": "^1.0.0",
     "app-root-path": "^3.0.0",
+    "async": "^3.2.0",
     "axios": "^0.20.0",
     "bcryptjs": "^2.4.3",
     "compression": "^1.7.4",
diff --git a/server/src/api/controllers/BaseController.ts b/server/src/api/controllers/BaseController.ts
index 4d3bb8b3e..e891ea893 100644
--- a/server/src/api/controllers/BaseController.ts
+++ b/server/src/api/controllers/BaseController.ts
@@ -5,7 +5,6 @@ import { mapKeysDeep } from 'utils'
 import asyncMiddleware from 'api/middleware/asyncMiddleware';
 
 export default class BaseController {
-
   /**
    * Converts plain object keys to cameCase style.
    * @param {Object} data 
@@ -75,6 +74,10 @@ export default class BaseController {
     return response;
   }
 
+  /**
+   * Async middleware.
+   * @param {function} callback 
+   */
   asyncMiddleware(callback) {
     return asyncMiddleware(callback);
   }
diff --git a/server/src/api/controllers/ManualJournals.ts b/server/src/api/controllers/ManualJournals.ts
index 266bddcaf..5bff2449c 100644
--- a/server/src/api/controllers/ManualJournals.ts
+++ b/server/src/api/controllers/ManualJournals.ts
@@ -245,7 +245,7 @@ export default class ManualJournalsController extends BaseController {
         manualJournalId
       );
       return res.status(200).send({
-        manual_journal: manualJournal
+        manual_journal: manualJournal,
       });
     } catch (error) {
       next(error);
@@ -449,14 +449,25 @@ export default class ManualJournalsController extends BaseController {
           ],
         });
       }
+      if (error.errorType === 'CONTACTS_SHOULD_ASSIGN_WITH_VALID_ACCOUNT') {
+        return res.boom.badRequest('', {
+          errors: [
+            {
+              type: 'CONTACTS_SHOULD_ASSIGN_WITH_VALID_ACCOUNT',
+              code: 700,
+              meta: this.transfromToResponse(error.payload),
+            },
+          ],
+        });
+      }
       if (error.errorType === 'contacts_not_found') {
         return res.boom.badRequest('', {
-          errors: [{ type: 'CONTACTS_NOT_FOUND', code: 700 }],
+          errors: [{ type: 'CONTACTS_NOT_FOUND', code: 800 }],
         });
       }
       if (error.errorType === 'MANUAL_JOURNAL_ALREADY_PUBLISHED') {
         return res.boom.badRequest('', {
-          errors: [{ type: 'MANUAL_JOURNAL_ALREADY_PUBLISHED', code: 800 }],
+          errors: [{ type: 'MANUAL_JOURNAL_ALREADY_PUBLISHED', code: 900 }],
         });
       }
     }
diff --git a/server/src/api/controllers/Sales/SalesInvoices.ts b/server/src/api/controllers/Sales/SalesInvoices.ts
index ff8216b66..8db65f6c6 100644
--- a/server/src/api/controllers/Sales/SalesInvoices.ts
+++ b/server/src/api/controllers/Sales/SalesInvoices.ts
@@ -106,8 +106,14 @@ export default class SaleInvoicesController extends BaseController {
       check('entries.*.item_id').exists().isNumeric().toInt(),
       check('entries.*.rate').exists().isNumeric().toFloat(),
       check('entries.*.quantity').exists().isNumeric().toFloat(),
-      check('entries.*.discount').optional({ nullable: true }).isNumeric().toFloat(),
-      check('entries.*.description').optional({ nullable: true }).trim().escape(),
+      check('entries.*.discount')
+        .optional({ nullable: true })
+        .isNumeric()
+        .toFloat(),
+      check('entries.*.description')
+        .optional({ nullable: true })
+        .trim()
+        .escape(),
     ];
   }
 
@@ -230,7 +236,11 @@ export default class SaleInvoicesController extends BaseController {
 
     try {
       // Deletes the sale invoice with associated entries and journal transaction.
-      await this.saleInvoiceService.deleteSaleInvoice(tenantId, saleInvoiceId, user);
+      await this.saleInvoiceService.deleteSaleInvoice(
+        tenantId,
+        saleInvoiceId,
+        user
+      );
 
       return res.status(200).send({
         id: saleInvoiceId,
@@ -402,15 +412,23 @@ export default class SaleInvoicesController extends BaseController {
       }
       if (error.errorType === 'SALE_ESTIMATE_NOT_FOUND') {
         return res.boom.badRequest(null, {
-          errors: [
-            { type: 'FROM_SALE_ESTIMATE_NOT_FOUND', code: 1200 },
-          ],
+          errors: [{ type: 'FROM_SALE_ESTIMATE_NOT_FOUND', code: 1200 }],
         });
       }
       if (error.errorType === 'SALE_ESTIMATE_CONVERTED_TO_INVOICE') {
         return res.boom.badRequest(null, {
           errors: [
-            { type: 'SALE_ESTIMATE_IS_ALREADY_CONVERTED_TO_INVOICE', code: 1300 },
+            {
+              type: 'SALE_ESTIMATE_IS_ALREADY_CONVERTED_TO_INVOICE',
+              code: 1300,
+            },
+          ],
+        });
+      }
+      if (error.errorType === 'INVOICE_AMOUNT_SMALLER_THAN_PAYMENT_AMOUNT') {
+        return res.boom.badRequest(null, {
+          errors: [
+            { type: 'INVOICE_AMOUNT_SMALLER_THAN_PAYMENT_AMOUNT', code: 1400 },
           ],
         });
       }
diff --git a/server/src/api/controllers/Subscription/Licenses.ts b/server/src/api/controllers/Subscription/Licenses.ts
index ace83a13a..6db07831e 100644
--- a/server/src/api/controllers/Subscription/Licenses.ts
+++ b/server/src/api/controllers/Subscription/Licenses.ts
@@ -28,7 +28,6 @@ export default class LicensesController extends BaseController {
         challenge: true,
       })
     );
-
     router.post(
       '/generate',
       this.generateLicenseSchema,
diff --git a/server/src/loaders/events.ts b/server/src/loaders/events.ts
index 2b1f8d323..e0478145f 100644
--- a/server/src/loaders/events.ts
+++ b/server/src/loaders/events.ts
@@ -7,12 +7,10 @@ import 'subscribers/manualJournals';
 import 'subscribers/expenses';
 
 import 'subscribers/Bills';
-import 'subscribers/Bills/SyncVendorsBalances';
 import 'subscribers/Bills/WriteJournalEntries';
 import 'subscribers/Bills/WriteInventoryTransactions';
 
 import 'subscribers/SaleInvoices';
-import 'subscribers/SaleInvoices/SyncCustomersBalance';
 import 'subscribers/SaleInvoices/WriteInventoryTransactions';
 import 'subscribers/SaleInvoices/WriteJournalEntries';
 
diff --git a/server/src/models/Contact.js b/server/src/models/Contact.js
index fb92f8471..fb4953ef5 100644
--- a/server/src/models/Contact.js
+++ b/server/src/models/Contact.js
@@ -20,7 +20,25 @@ export default class Contact extends TenantModel {
    * Defined virtual attributes.
    */
   static get virtualAttributes() {
-    return ['closingBalance'];
+    return ['contactNormal', 'closingBalance'];
+  }
+
+  /**
+   * Retrieve the contact normal by the given contact type.
+   */
+  static getContactNormalByType(contactType) {
+    const types = {
+      'vendor': 'credit',
+      'customer': 'debit',
+    };
+    return types[contactType];
+  }
+
+  /**
+   * Retrieve the contact noraml;
+   */
+  get contactNormal() {
+    return Contact.getContactNormalByType(this.contactService);
   }
 
   /**
diff --git a/server/src/models/Customer.js b/server/src/models/Customer.js
index 65137b63f..70c9092a1 100644
--- a/server/src/models/Customer.js
+++ b/server/src/models/Customer.js
@@ -41,7 +41,7 @@ export default class Customer extends TenantModel {
    * Defined virtual attributes.
    */
   static get virtualAttributes() {
-    return ['closingBalance'];
+    return ['closingBalance', 'contactNormal'];
   }
 
   /**
@@ -51,6 +51,13 @@ export default class Customer extends TenantModel {
     return this.openingBalance + this.balance;
   }
 
+  /**
+   * Retrieve the contact noraml;
+   */
+  get contactNormal() {
+    return 'debit';
+  }
+
   /**
    * Model modifiers.
    */
diff --git a/server/src/models/Vendor.js b/server/src/models/Vendor.js
index 5e5ee96fb..d56d6f390 100644
--- a/server/src/models/Vendor.js
+++ b/server/src/models/Vendor.js
@@ -40,7 +40,7 @@ export default class Vendor extends TenantModel {
    * Defined virtual attributes.
    */
   static get virtualAttributes() {
-    return ['closingBalance'];
+    return ['closingBalance', 'contactNormal'];
   }
 
   /**
@@ -50,6 +50,13 @@ export default class Vendor extends TenantModel {
     return this.openingBalance + this.balance;
   }
 
+  /**
+   * Retrieve the contact noraml;
+   */
+  get contactNormal() {
+    return 'debit';
+  }
+
   /**
    * Model modifiers.
    */
diff --git a/server/src/services/Accounting/JournalCommands.ts b/server/src/services/Accounting/JournalCommands.ts
index 9453a34d7..5a3135fa5 100644
--- a/server/src/services/Accounting/JournalCommands.ts
+++ b/server/src/services/Accounting/JournalCommands.ts
@@ -17,7 +17,6 @@ import {
 
 export default class JournalCommands {
   journal: JournalPoster;
-
   models: any;
   repositories: any;
 
@@ -77,7 +76,6 @@ export default class JournalCommands {
       credit: bill.amount,
       account: payableAccount.id,
       contactId: bill.vendorId,
-      contactType: 'Vendor',
       index: 1,
     });
     this.journal.credit(payableEntry);
@@ -113,8 +111,8 @@ export default class JournalCommands {
   ) {
     const { accountRepository } = this.repositories;
 
-    const openingBalanceAccount = await accountRepository.findOne({
-      slug: 'opening-balance',
+    const incomeAccount = await accountRepository.findOne({
+      slug: 'other-income',
     });
     const receivableAccount = await accountRepository.findOne({
       slug: 'accounts-receivable',
@@ -123,8 +121,6 @@ export default class JournalCommands {
     const commonEntry = {
       referenceType: 'CustomerOpeningBalance',
       referenceId: customerId,
-      contactType: 'Customer',
-      contactId: customerId,
       date: openingBalanceAt,
       userId,
     };
@@ -133,13 +129,14 @@ export default class JournalCommands {
       credit: 0,
       debit: openingBalance,
       account: receivableAccount.id,
+      contactId: customerId,
       index: 1,
     });
     const creditEntry = new JournalEntry({
       ...commonEntry,
       credit: openingBalance,
       debit: 0,
-      account: openingBalanceAccount.id,
+      account: incomeAccount.id,
       index: 2,
     });
     this.journal.debit(debitEntry);
@@ -171,8 +168,6 @@ export default class JournalCommands {
     const commonEntry = {
       referenceType: 'VendorOpeningBalance',
       referenceId: vendorId,
-      contactType: 'Vendor',
-      contactId: vendorId,
       date: openingBalanceAt,
       userId: authorizedUserId,
     };
@@ -182,6 +177,7 @@ export default class JournalCommands {
       credit: openingBalance,
       debit: 0,
       index: 1,
+      contactId: vendorId,
     });
     const debitEntry = new JournalEntry({
       ...commonEntry,
@@ -297,7 +293,6 @@ export default class JournalCommands {
         account: entry.accountId,
         referenceType: 'Journal',
         referenceId: manualJournalObj.id,
-        contactType: entry.contactType,
         contactId: entry.contactId,
         note: entry.note,
         date: manualJournalObj.date,
@@ -379,6 +374,7 @@ export default class JournalCommands {
       ...commonEntry,
       debit: saleInvoice.balance,
       account: receivableAccountId,
+      contactId: saleInvoice.customerId,
       index: 1,
     });
     this.journal.debit(receivableEntry);
diff --git a/server/src/services/Accounting/JournalContacts.ts b/server/src/services/Accounting/JournalContacts.ts
new file mode 100644
index 000000000..6ae2b22c5
--- /dev/null
+++ b/server/src/services/Accounting/JournalContacts.ts
@@ -0,0 +1,74 @@
+import async from 'async';
+
+export default class JournalContacts {
+  saveContactBalanceQueue: any;
+  contactsBalanceTable: {
+    [key: number]: { credit: number; debit: number };
+  } = {};
+
+  constructor(journal) {
+    this.journal = journal;
+    this.saveContactBalanceQueue = async.queue(
+      this.saveContactBalanceChangeTask.bind(this),
+      10
+    );
+  }
+  /**
+   * Sets the contact balance change.
+   */
+  private getContactsBalanceChanges(entry) {
+    if (!entry.contactId) {
+      return;
+    }
+    const change = {
+      debit: entry.debit,
+      credit: entry.credit,
+    };
+    if (!this.contactsBalanceTable[entry.contactId]) {
+      this.contactsBalanceTable[entry.contactId] = { credit: 0, debit: 0 };
+    }
+    if (change.credit) {
+      this.contactsBalanceTable[entry.contactId].credit += change.credit;
+    }
+    if (change.debit) {
+      this.contactsBalanceTable[entry.contactId].debit += change.debit;
+    }
+  }
+
+  /**
+   * Save contacts balance change.
+   */
+  saveContactsBalance() {
+    const balanceChanges = Object.entries(
+      this.contactsBalanceTable
+    ).map(([contactId, { credit, debit }]) => ({ contactId, credit, debit }));
+
+    return this.saveContactBalanceQueue.pushAsync(balanceChanges);
+  }
+
+  /**
+   * Saves contact balance change task.
+   * @param {number} contactId - Contact id.
+   * @param {number} credit - Credit amount.
+   * @param {number} debit - Debit amount.
+   */
+  async saveContactBalanceChangeTask({ contactId, credit, debit }, callback) {
+    const { contactRepository } = this.repositories;
+
+    const contact = await contactRepository.findOneById(contactId);
+    let balanceChange = 0;
+
+    if (contact.contactNormal === 'credit') {
+      balanceChange += credit - debit;
+    } else {
+      balanceChange += debit - credit;
+    }
+    // Contact change balance.
+    await contactRepository.changeNumber(
+      { id: contactId },
+      'balance',
+      balanceChange
+    );
+    callback();
+  }
+}
diff --git a/server/src/services/Accounting/JournalFinancial.ts b/server/src/services/Accounting/JournalFinancial.ts
index 6de40e8f8..8cdaeea8a 100644
--- a/server/src/services/Accounting/JournalFinancial.ts
+++ b/server/src/services/Accounting/JournalFinancial.ts
@@ -14,6 +14,4 @@ export default class JournalFinancial {
     this.journal = journal;
     this.accountsDepGraph = this.journal.accountsDepGraph;
   }
-
-
 }
\ No newline at end of file
diff --git a/server/src/services/Accounting/JournalPoster.ts b/server/src/services/Accounting/JournalPoster.ts
index c1fa61623..9ed95cdfa 100644
--- a/server/src/services/Accounting/JournalPoster.ts
+++ b/server/src/services/Accounting/JournalPoster.ts
@@ -1,6 +1,7 @@
-import { omit, get } from 'lodash';
+import { omit, get, chain } from 'lodash';
 import moment from 'moment';
 import { Container } from 'typedi';
+import async from 'async';
 import JournalEntry from 'services/Accounting/JournalEntry';
 import TenancyService from 'services/Tenancy/TenancyService';
 import {
@@ -11,6 +12,19 @@ import {
   TEntryType,
 } from 'interfaces';
 
+const CONTACTS_CONFIG = [
+  {
+    accountBySlug: 'accounts-receivable',
+    contactService: 'customer',
+    assignRequired: true,
+  },
+  {
+    accountBySlug: 'accounts-payable',
+    contactService: 'vendor',
+    assignRequired: true,
+  },
+];
+
 export default class JournalPoster implements IJournalPoster {
   tenantId: number;
   tenancy: TenancyService;
@@ -24,6 +38,10 @@ export default class JournalPoster implements IJournalPoster {
   accountsDepGraph: IAccountsChange;
 
   accountsBalanceTable: { [key: number]: number } = {};
+  contactsBalanceTable: {
+    [key: number]: { credit: number; debit: number }[];
+  } = {};
+  saveContactBalanceQueue: any;
 
   /**
    * Journal poster constructor.
@@ -39,6 +57,10 @@ export default class JournalPoster implements IJournalPoster {
     if (accountsGraph) {
       this.accountsDepGraph = accountsGraph;
     }
+    this.saveContactBalanceQueue = async.queue(
+      this.saveContactBalanceChangeTask.bind(this),
+      10
+    );
   }
 
   /**
@@ -69,7 +91,7 @@ export default class JournalPoster implements IJournalPoster {
   }
 
   /**
-   *
+   * Detarmines the ledger is empty.
    */
   public isEmpty() {
     return this.entries.length === 0;
@@ -85,6 +107,7 @@ export default class JournalPoster implements IJournalPoster {
     }
     this.entries.push(entryModel.entry);
     this.setAccountBalanceChange(entryModel.entry);
+    this.setContactBalanceChange(entryModel.entry);
   }
 
   /**
@@ -97,6 +120,83 @@ export default class JournalPoster implements IJournalPoster {
     }
     this.entries.push(entryModel.entry);
     this.setAccountBalanceChange(entryModel.entry);
+    this.setContactBalanceChange(entryModel.entry);
+  }
+
+  /**
+   * Sets the contact balance change.
+   */
+  private setContactBalanceChange(entry) {
+    if (!entry.contactId) {
+      return;
+    }
+    const change = {
+      debit: entry.debit || 0,
+      credit: entry.credit || 0,
+      account: entry.account,
+    };
+    if (!this.contactsBalanceTable[entry.contactId]) {
+      this.contactsBalanceTable[entry.contactId] = [];
+    }
+    this.contactsBalanceTable[entry.contactId].push(change);
+  }
+
+  /**
+   * Save contacts balance change.
+   */
+  async saveContactsBalance() {
+    await this.initAccountsDepGraph();
+
+    const balanceChanges = Object.entries(this.contactsBalanceTable).map(
+      ([contactId, entries]) => ({
+        contactId,
+        entries: entries.filter((entry) => {
+          const account = this.accountsDepGraph.getNodeData(entry.account);
+
+          return (
+            account &&
+            CONTACTS_CONFIG.some((config) => {
+              return config.accountBySlug === account.slug;
+            })
+          );
+        }),
+      })
+    );
+
+    const balanceEntries = chain(balanceChanges)
+      .map((change) => change.entries.map(entry => ({
+        ...entry,
+        contactId: change.contactId
+      })))
+      .flatten()
+      .value();
+
+    return this.saveContactBalanceQueue.pushAsync(balanceEntries);
+  }
+
+  /**
+   * Saves contact balance change task.
+   * @param {number} contactId - Contact id.
+   * @param {number} credit - Credit amount.
+   * @param {number} debit - Debit amount.
+   */
+  async saveContactBalanceChangeTask({ contactId, credit, debit }) {
+    const { contactRepository } = this.repositories;
+
+    const contact = await contactRepository.findOneById(contactId);
+    let balanceChange = 0;
+
+    if (contact.contactNormal === 'credit') {
+      balanceChange += credit - debit;
+    } else {
+      balanceChange += debit - credit;
+    }
+    // Contact change balance.
+    await contactRepository.changeNumber(
+      { id: contactId },
+      'balance',
+      balanceChange
+    );
   }
 
   /**
@@ -321,7 +421,8 @@ export default class JournalPoster implements IJournalPoster {
       entry.credit = -1 * entry.credit;
       entry.debit = -1 * entry.debit;
 
-      this.setAccountBalanceChange(entry, entry.accountNormal);
+      this.setAccountBalanceChange(entry);
+      this.setContactBalanceChange(entry);
     });
     this.deletedEntriesIds.push(...removeEntries.map((entry) => entry.id));
   }
diff --git a/server/src/services/Contacts/ContactsService.ts b/server/src/services/Contacts/ContactsService.ts
index e398bcc2f..3b962bd0b 100644
--- a/server/src/services/Contacts/ContactsService.ts
+++ b/server/src/services/Contacts/ContactsService.ts
@@ -240,7 +240,10 @@ export default class ContactsService {
     journal.fromTransactions(contactsTransactions);
     journal.removeEntries();
 
-    await Promise.all([journal.saveBalance(), journal.deleteEntries()]);
+    await Promise.all([
+      journal.saveBalance(),
+      journal.deleteEntries(),
+    ]);
   }
 
   /**
diff --git a/server/src/services/Contacts/CustomersService.ts b/server/src/services/Contacts/CustomersService.ts
index 8b05da20e..5157582e2 100644
--- a/server/src/services/Contacts/CustomersService.ts
+++ b/server/src/services/Contacts/CustomersService.ts
@@ -268,7 +268,11 @@ export default class CustomersService {
       openingBalanceAt,
       authorizedUserId
     );
-    await Promise.all([journal.saveBalance(), journal.saveEntries()]);
+    await Promise.all([
+      journal.saveBalance(),
+      journal.saveEntries(),
+      journal.saveContactsBalance(),
+    ]);
   }
 
   /**
diff --git a/server/src/services/Contacts/VendorsService.ts b/server/src/services/Contacts/VendorsService.ts
index 178498fd5..052505823 100644
--- a/server/src/services/Contacts/VendorsService.ts
+++ b/server/src/services/Contacts/VendorsService.ts
@@ -192,7 +192,11 @@ export default class VendorsService {
       openingBalanceAt,
       user
     );
-    await Promise.all([journal.saveBalance(), journal.saveEntries()]);
+    await Promise.all([
+      journal.saveBalance(),
+      journal.saveEntries(),
+      journal.saveContactsBalance(),
+    ]);
   }
 
   /**
diff --git a/server/src/services/Items/ItemsService.ts b/server/src/services/Items/ItemsService.ts
index 813aa0c77..f6d91557a 100644
--- a/server/src/services/Items/ItemsService.ts
+++ b/server/src/services/Items/ItemsService.ts
@@ -10,29 +10,12 @@ import DynamicListingService from 'services/DynamicListing/DynamicListService';
 import TenancyService from 'services/Tenancy/TenancyService';
 import { ServiceError } from 'exceptions';
 import InventoryService from 'services/Inventory/Inventory';
-import { ACCOUNT_PARENT_TYPE, ACCOUNT_ROOT_TYPE, ACCOUNT_TYPE } from 'data/AccountTypes'
-
-const ERRORS = {
-  NOT_FOUND: 'NOT_FOUND',
-  ITEMS_NOT_FOUND: 'ITEMS_NOT_FOUND',
-
-  ITEM_NAME_EXISTS: 'ITEM_NAME_EXISTS',
-  ITEM_CATEOGRY_NOT_FOUND: 'ITEM_CATEOGRY_NOT_FOUND',
-  COST_ACCOUNT_NOT_COGS: 'COST_ACCOUNT_NOT_COGS',
-  COST_ACCOUNT_NOT_FOUMD: 'COST_ACCOUNT_NOT_FOUMD',
-  SELL_ACCOUNT_NOT_FOUND: 'SELL_ACCOUNT_NOT_FOUND',
-  SELL_ACCOUNT_NOT_INCOME: 'SELL_ACCOUNT_NOT_INCOME',
-
-  INVENTORY_ACCOUNT_NOT_FOUND: 'INVENTORY_ACCOUNT_NOT_FOUND',
-  INVENTORY_ACCOUNT_NOT_INVENTORY: 'INVENTORY_ACCOUNT_NOT_INVENTORY',
-
-  ITEMS_HAVE_ASSOCIATED_TRANSACTIONS: 'ITEMS_HAVE_ASSOCIATED_TRANSACTIONS',
-  ITEM_HAS_ASSOCIATED_TRANSACTINS: 'ITEM_HAS_ASSOCIATED_TRANSACTINS',
-
-  ITEM_HAS_ASSOCIATED_INVENTORY_ADJUSTMENT:
-    'ITEM_HAS_ASSOCIATED_INVENTORY_ADJUSTMENT',
-};
-
+import {
+  ACCOUNT_PARENT_TYPE,
+  ACCOUNT_ROOT_TYPE,
+  ACCOUNT_TYPE,
+} from 'data/AccountTypes';
+import { ERRORS } from './constants';
 @Service()
 export default class ItemsService implements IItemsService {
   @Inject()
@@ -130,7 +113,7 @@ export default class ItemsService implements IItemsService {
       });
       throw new ServiceError(ERRORS.COST_ACCOUNT_NOT_FOUMD);
 
-    // Detarmines the cost of goods sold account.
+      // Detarmines the cost of goods sold account.
     } else if (!foundAccount.isParentType(ACCOUNT_PARENT_TYPE.EXPENSE)) {
       this.logger.info('[items] validate cost account not COGS type.', {
         tenantId,
@@ -149,9 +132,7 @@ export default class ItemsService implements IItemsService {
     tenantId: number,
     sellAccountId: number
   ) {
-    const {
-      accountRepository,
-    } = this.tenancy.repositories(tenantId);
+    const { accountRepository } = this.tenancy.repositories(tenantId);
 
     this.logger.info('[items] validate sell account existance.', {
       tenantId,
@@ -166,7 +147,6 @@ export default class ItemsService implements IItemsService {
         sellAccountId,
       });
       throw new ServiceError(ERRORS.SELL_ACCOUNT_NOT_FOUND);
-      
     } else if (!foundAccount.isParentType(ACCOUNT_ROOT_TYPE.INCOME)) {
       this.logger.info('[items] sell account not income type.', {
         tenantId,
@@ -185,9 +165,7 @@ export default class ItemsService implements IItemsService {
     tenantId: number,
     inventoryAccountId: number
   ) {
-    const {
-      accountRepository,
-    } = this.tenancy.repositories(tenantId);
+    const { accountRepository } = this.tenancy.repositories(tenantId);
 
     this.logger.info('[items] validate inventory account existance.', {
       tenantId,
@@ -203,7 +181,6 @@ export default class ItemsService implements IItemsService {
         inventoryAccountId,
       });
       throw new ServiceError(ERRORS.INVENTORY_ACCOUNT_NOT_FOUND);
-
     } else if (!foundAccount.isAccountType(ACCOUNT_TYPE.INVENTORY)) {
       this.logger.info('[items] inventory account not inventory type.', {
         tenantId,
diff --git a/server/src/services/Items/constants.ts b/server/src/services/Items/constants.ts
new file mode 100644
index 000000000..927137e8a
--- /dev/null
+++ b/server/src/services/Items/constants.ts
@@ -0,0 +1,21 @@
+
+export const ERRORS = {
+  NOT_FOUND: 'NOT_FOUND',
+  ITEMS_NOT_FOUND: 'ITEMS_NOT_FOUND',
+
+  ITEM_NAME_EXISTS: 'ITEM_NAME_EXISTS',
+  ITEM_CATEOGRY_NOT_FOUND: 'ITEM_CATEOGRY_NOT_FOUND',
+  COST_ACCOUNT_NOT_COGS: 'COST_ACCOUNT_NOT_COGS',
+  COST_ACCOUNT_NOT_FOUMD: 'COST_ACCOUNT_NOT_FOUMD',
+  SELL_ACCOUNT_NOT_FOUND: 'SELL_ACCOUNT_NOT_FOUND',
+  SELL_ACCOUNT_NOT_INCOME: 'SELL_ACCOUNT_NOT_INCOME',
+
+  INVENTORY_ACCOUNT_NOT_FOUND: 'INVENTORY_ACCOUNT_NOT_FOUND',
+  INVENTORY_ACCOUNT_NOT_INVENTORY: 'INVENTORY_ACCOUNT_NOT_INVENTORY',
+
+  ITEMS_HAVE_ASSOCIATED_TRANSACTIONS: 'ITEMS_HAVE_ASSOCIATED_TRANSACTIONS',
+  ITEM_HAS_ASSOCIATED_TRANSACTINS: 'ITEM_HAS_ASSOCIATED_TRANSACTINS',
+
+  ITEM_HAS_ASSOCIATED_INVENTORY_ADJUSTMENT:
+    'ITEM_HAS_ASSOCIATED_INVENTORY_ADJUSTMENT',
+};
diff --git a/server/src/services/ManualJournals/ManualJournalsService.ts b/server/src/services/ManualJournals/ManualJournalsService.ts
index d46cdaa01..be7737b95 100644
--- a/server/src/services/ManualJournals/ManualJournalsService.ts
+++ b/server/src/services/ManualJournals/ManualJournalsService.ts
@@ -9,6 +9,7 @@ import {
   ISystemUser,
   IManualJournal,
   IPaginationMeta,
+  IManualJournalEntry,
 } from 'interfaces';
 import TenancyService from 'services/Tenancy/TenancyService';
 import DynamicListingService from 'services/DynamicListing/DynamicListService';
@@ -20,30 +21,7 @@ import {
 import JournalPoster from 'services/Accounting/JournalPoster';
 import JournalCommands from 'services/Accounting/JournalCommands';
 import JournalPosterService from 'services/Sales/JournalPosterService';
-
-const ERRORS = {
-  NOT_FOUND: 'manual_journal_not_found',
-  CREDIT_DEBIT_NOT_EQUAL_ZERO: 'credit_debit_not_equal_zero',
-  CREDIT_DEBIT_NOT_EQUAL: 'credit_debit_not_equal',
-  ACCCOUNTS_IDS_NOT_FOUND: 'acccounts_ids_not_found',
-  JOURNAL_NUMBER_EXISTS: 'journal_number_exists',
-  ENTRIES_SHOULD_ASSIGN_WITH_CONTACT: 'ENTRIES_SHOULD_ASSIGN_WITH_CONTACT',
-  CONTACTS_NOT_FOUND: 'contacts_not_found',
-  MANUAL_JOURNAL_ALREADY_PUBLISHED: 'MANUAL_JOURNAL_ALREADY_PUBLISHED',
-};
-
-const CONTACTS_CONFIG = [
-  {
-    accountBySlug: 'accounts-receivable',
-    contactService: 'customer',
-    assignRequired: false,
-  },
-  {
-    accountBySlug: 'accounts-payable',
-    contactService: 'vendor',
-    assignRequired: true,
-  },
-];
+import { ERRORS } from './constants';
 
 @Service()
 export default class ManualJournalsService implements IManualJournalsService {
@@ -159,8 +137,7 @@ export default class ManualJournalsService implements IManualJournalsService {
     const { Account } = this.tenancy.models(tenantId);
     const manualAccountsIds = manualJournalDTO.entries.map((e) => e.accountId);
 
-    const accounts = await Account.query()
-      .whereIn('id', manualAccountsIds);
+    const accounts = await Account.query().whereIn('id', manualAccountsIds);
 
     const storedAccountsIds = accounts.map((account) => account.id);
 
@@ -203,29 +180,37 @@ export default class ManualJournalsService implements IManualJournalsService {
    * @param {string} accountBySlug
    * @param {string} contactType
    */
-  private async validateAccountsWithContactType(
+  private async validateAccountWithContactType(
     tenantId: number,
-    manualJournalDTO: IManualJournalDTO,
-    accountBySlug: string,
-    contactType: string,
-    contactRequired: boolean = true
-  ): Promise<void> {
-    const { accountRepository } = this.tenancy.repositories(tenantId);
-    const payableAccount = await accountRepository.findOne({
-      slug: accountBySlug,
-    });
+    entriesDTO: IManualJournalEntry[],
 
-    const entriesHasNoVendorContact = manualJournalDTO.entries.filter(
-      (e) =>
-        e.accountId === payableAccount.id &&
-        ((!e.contactId && contactRequired) || e.contactType !== contactType)
+    accountBySlug: string,
+    contactType: string
+  ): Promise<void> {
+    const { Account, Contact } = this.tenancy.models(tenantId);
+
+    // Retrieve account meta by the given account slug.
+    const account = await Account.query().findOne('slug', accountBySlug);
+
+    // Filter all entries of the given account.
+    const accountEntries = entriesDTO.filter(
+      (entry) => entry.accountId === account.id
     );
-    if (entriesHasNoVendorContact.length > 0) {
-      const indexes = entriesHasNoVendorContact.map((e) => e.index);
+    // Can't continue if there is no entry that associate to the given account.
+    if (accountEntries.length === 0) {
+      return;
+    }
+    // Filter entries that have no contact type or not equal the valid type.
+    const entriesNoContact = accountEntries.filter(
+      (entry) => !entry.contactType || entry.contactType !== contactType
+    );
+    // Throw error in case one of entries that has invalid contact type.
+    if (entriesNoContact.length > 0) {
+      const indexes = entriesNoContact.map(e => e.index);
 
       throw new ServiceError(ERRORS.ENTRIES_SHOULD_ASSIGN_WITH_CONTACT, '', {
+        accountSlug: accountBySlug,
         contactType,
-        accountBySlug,
         indexes,
       });
     }
@@ -238,19 +223,22 @@ export default class ManualJournalsService implements IManualJournalsService {
    */
   private async dynamicValidateAccountsWithContactType(
     tenantId: number,
-    manualJournalDTO: IManualJournalDTO
+    entriesDTO: IManualJournalEntry[]
   ): Promise<any> {
-    return Promise.all(
-      CONTACTS_CONFIG.map(({ accountBySlug, contactService, assignRequired }) =>
-        this.validateAccountsWithContactType(
-          tenantId,
-          manualJournalDTO,
-          accountBySlug,
-          contactService,
-          assignRequired
-        )
-      )
-    );
+    return Promise.all([
+      this.validateAccountWithContactType(
+        tenantId,
+        entriesDTO,
+        'accounts-receivable',
+        'customer'
+      ),
+      this.validateAccountWithContactType(
+        tenantId,
+        entriesDTO,
+        'accounts-payable',
+        'vendor'
+      ),
+    ]);
   }
 
   /**
@@ -273,9 +261,9 @@ export default class ManualJournalsService implements IManualJournalsService {
       const entriesContactsIds = entriesContactPairs.map(
         (entry) => entry.contactId
       );
-
       // Retrieve all stored contacts on the storage from contacts entries.
-      const storedContacts = await contactRepository.findByIds(
+      const storedContacts = await contactRepository.findWhereIn(
+        'id',
         entriesContactsIds
       );
       // Converts the stored contacts to map with id as key and entry as value.
@@ -287,8 +275,7 @@ export default class ManualJournalsService implements IManualJournalsService {
       entriesContactPairs.forEach((contactEntry) => {
         const storedContact = storedContactsMap.get(contactEntry.contactId);
 
-        // in case the contact id not found or contact type no equals pushed to
-        // not found contacts.
+        // in case the contact id not found.
         if (
           !storedContact ||
           storedContact.contactService !== contactEntry.contactType
@@ -378,7 +365,7 @@ export default class ManualJournalsService implements IManualJournalsService {
     // Validate accounts with contact type from the given config.
     await this.dynamicValidateAccountsWithContactType(
       tenantId,
-      manualJournalDTO
+      manualJournalDTO.entries
     );
     this.logger.info(
       '[manual_journal] trying to save manual journal to the storage.',
@@ -446,7 +433,7 @@ export default class ManualJournalsService implements IManualJournalsService {
     // Validate accounts with contact type from the given config.
     await this.dynamicValidateAccountsWithContactType(
       tenantId,
-      manualJournalDTO
+      manualJournalDTO.entries
     );
     // Transform manual journal DTO to model.
     const manualJournalObj = this.transformEditDTOToModel(
@@ -525,7 +512,7 @@ export default class ManualJournalsService implements IManualJournalsService {
     tenantId: number,
     manualJournalsIds: number[]
   ): Promise<{
-    oldManualJournals: IManualJournal[]
+    oldManualJournals: IManualJournal[];
   }> {
     const { ManualJournal, ManualJournalEntry } = this.tenancy.models(tenantId);
 
@@ -817,6 +804,7 @@ export default class ManualJournalsService implements IManualJournalsService {
       journal.saveBalance(),
       journal.deleteEntries(),
       journal.saveEntries(),
+      journal.saveContactsBalance(),
     ]);
     this.logger.info(
       '[manual_journal] the journal entries saved successfully.',
diff --git a/server/src/services/ManualJournals/constants.ts b/server/src/services/ManualJournals/constants.ts
new file mode 100644
index 000000000..788323e03
--- /dev/null
+++ b/server/src/services/ManualJournals/constants.ts
@@ -0,0 +1,24 @@
+export const ERRORS = {
+  NOT_FOUND: 'manual_journal_not_found',
+  CREDIT_DEBIT_NOT_EQUAL_ZERO: 'credit_debit_not_equal_zero',
+  CREDIT_DEBIT_NOT_EQUAL: 'credit_debit_not_equal',
+  ACCCOUNTS_IDS_NOT_FOUND: 'acccounts_ids_not_found',
+  JOURNAL_NUMBER_EXISTS: 'journal_number_exists',
+  ENTRIES_SHOULD_ASSIGN_WITH_CONTACT: 'ENTRIES_SHOULD_ASSIGN_WITH_CONTACT',
+  CONTACTS_NOT_FOUND: 'contacts_not_found',
+  ENTRIES_CONTACTS_NOT_FOUND: 'ENTRIES_CONTACTS_NOT_FOUND',
+  MANUAL_JOURNAL_ALREADY_PUBLISHED: 'MANUAL_JOURNAL_ALREADY_PUBLISHED',
+};
+
+export const CONTACTS_CONFIG = [
+  {
+    accountBySlug: 'accounts-receivable',
+    contactService: 'customer',
+    assignRequired: true,
+  },
+  {
+    accountBySlug: 'accounts-payable',
+    contactService: 'vendor',
+    assignRequired: true,
+  },
+];
diff --git a/server/src/services/Purchases/BillPayments.ts b/server/src/services/Purchases/BillPayments.ts
index b126b3144..d229bcddc 100644
--- a/server/src/services/Purchases/BillPayments.ts
+++ b/server/src/services/Purchases/BillPayments.ts
@@ -27,7 +27,6 @@ import DynamicListingService from 'services/DynamicListing/DynamicListService';
 import { entriesAmountDiff, formatDateFields } from 'utils';
 import { ServiceError } from 'exceptions';
 import { ACCOUNT_PARENT_TYPE } from 'data/AccountTypes';
-import PayableAgingSummaryService from 'services/FinancialStatements/AgingSummary/APAgingSummaryService';
 
 const ERRORS = {
   BILL_VENDOR_NOT_FOUND: 'VENDOR_NOT_FOUND',
@@ -452,6 +451,7 @@ export default class BillPaymentsService {
       .delete();
     await BillPayment.query().where('id', billPaymentId).delete();
 
+    // Triggers `onBillPaymentDeleted` event.
     await this.eventDispatcher.dispatch(events.billPayment.onDeleted, {
       tenantId,
       billPaymentId,
@@ -490,7 +490,8 @@ export default class BillPaymentsService {
    */
   public async recordJournalEntries(
     tenantId: number,
-    billPayment: IBillPayment
+    billPayment: IBillPayment,
+    override: boolean = false,
   ) {
     const { AccountTransaction } = this.tenancy.models(tenantId);
     const { accountRepository } = this.tenancy.repositories(tenantId);
@@ -498,7 +499,7 @@ export default class BillPaymentsService {
     const paymentAmount = sumBy(billPayment.entries, 'paymentAmount');
     const formattedDate = moment(billPayment.paymentDate).format('YYYY-MM-DD');
 
-    // Retrieve AP account from the storage.
+    // Retrieve A/P account from the storage.
     const payableAccount = await accountRepository.findOne({
       slug: 'accounts-payable',
     });
@@ -511,26 +512,27 @@ export default class BillPaymentsService {
       referenceType: 'BillPayment',
       date: formattedDate,
     };
-    if (billPayment.id) {
+    if (override) {
       const transactions = await AccountTransaction.query()
         .whereIn('reference_type', ['BillPayment'])
         .where('reference_id', billPayment.id)
         .withGraphFetched('account');
 
-      journal.loadEntries(transactions);
+      journal.fromTransactions(transactions);
       journal.removeEntries();
     }
     const debitReceivable = new JournalEntry({
       ...commonJournal,
       debit: paymentAmount,
-      contactType: 'Vendor',
       contactId: billPayment.vendorId,
       account: payableAccount.id,
+      index: 1,
     });
     const creditPaymentAccount = new JournalEntry({
       ...commonJournal,
       credit: paymentAmount,
       account: billPayment.paymentAccountId,
+      index: 2,
     });
     journal.debit(debitReceivable);
     journal.credit(creditPaymentAccount);
@@ -539,6 +541,7 @@ export default class BillPaymentsService {
       journal.deleteEntries(),
       journal.saveEntries(),
       journal.saveBalance(),
+      journal.saveContactsBalance(),
     ]);
   }
 
@@ -554,7 +557,11 @@ export default class BillPaymentsService {
 
     await journalCommands.revertJournalEntries(billPaymentId, 'BillPayment');
 
-    return Promise.all([journal.saveBalance(), journal.deleteEntries()]);
+    return Promise.all([
+      journal.saveBalance(),
+      journal.deleteEntries(),
+      journal.saveContactsBalance(),
+    ]);
   }
 
   /**
diff --git a/server/src/services/Purchases/Bills.ts b/server/src/services/Purchases/Bills.ts
index beeef28f4..1e44b3cdc 100644
--- a/server/src/services/Purchases/Bills.ts
+++ b/server/src/services/Purchases/Bills.ts
@@ -527,6 +527,7 @@ export default class BillsService extends SalesInvoicesCost {
       journal.deleteEntries(),
       journal.saveEntries(),
       journal.saveBalance(),
+      journal.saveContactsBalance(),
     ]);
   }
 
diff --git a/server/src/services/Sales/JournalPosterService.ts b/server/src/services/Sales/JournalPosterService.ts
index 403f75524..0be67c3d5 100644
--- a/server/src/services/Sales/JournalPosterService.ts
+++ b/server/src/services/Sales/JournalPosterService.ts
@@ -27,7 +27,8 @@ export default class JournalPosterService {
 
     await Promise.all([
       journal.deleteEntries(),
-      journal.saveBalance()
+      journal.saveBalance(),
+      journal.saveContactsBalance(),
     ]);
   }
 }
\ No newline at end of file
diff --git a/server/src/services/Sales/PaymentsReceives.ts b/server/src/services/Sales/PaymentsReceives.ts
index 99be07bd3..621bd4de6 100644
--- a/server/src/services/Sales/PaymentsReceives.ts
+++ b/server/src/services/Sales/PaymentsReceives.ts
@@ -16,7 +16,6 @@ import {
   IPaymentReceiveEntryDTO,
   IPaymentReceivesFilter,
   ISaleInvoice,
-  ISystemService,
   ISystemUser,
   IPaymentReceivePageEntry,
 } from 'interfaces';
@@ -496,7 +495,7 @@ export default class PaymentReceiveService {
     paymentReceiveId: number,
     authorizedUser: ISystemUser
   ): Promise<{
-    paymentReceive: Omit<IPaymentReceive, "entries">;
+    paymentReceive: Omit<IPaymentReceive, 'entries'>;
     entries: IPaymentReceivePageEntry[];
   }> {
     const { PaymentReceive, SaleInvoice } = this.tenancy.models(tenantId);
@@ -665,7 +664,6 @@ export default class PaymentReceiveService {
     const creditReceivable = new JournalEntry({
       ...commonJournal,
       credit: paymentAmount,
-      contactType: 'Customer',
       contactId: paymentReceive.customerId,
       account: receivableAccount.id,
       index: 1,
@@ -683,6 +681,7 @@ export default class PaymentReceiveService {
       journal.deleteEntries(),
       journal.saveEntries(),
       journal.saveBalance(),
+      journal.saveContactsBalance(),
     ]);
   }
 
@@ -705,7 +704,11 @@ export default class PaymentReceiveService {
 
     await commands.revertJournalEntries(paymentReceiveId, 'PaymentReceive');
 
-    await Promise.all([journal.saveBalance(), journal.deleteEntries()]);
+    await Promise.all([
+      journal.saveBalance(),
+      journal.deleteEntries(),
+      journal.saveContactsBalance(),
+    ]);
   }
 
   /**
diff --git a/server/src/services/Sales/SalesInvoices.ts b/server/src/services/Sales/SalesInvoices.ts
index ceff4c9a8..bbfa3a863 100644
--- a/server/src/services/Sales/SalesInvoices.ts
+++ b/server/src/services/Sales/SalesInvoices.ts
@@ -29,6 +29,7 @@ import ItemsEntriesService from 'services/Items/ItemsEntriesService';
 import CustomersService from 'services/Contacts/CustomersService';
 import SaleEstimateService from 'services/Sales/SalesEstimate';
 import JournalPosterService from './JournalPosterService';
+import SaleInvoiceRepository from 'repositories/SaleInvoiceRepository';
 
 const ERRORS = {
   INVOICE_NUMBER_NOT_UNIQUE: 'INVOICE_NUMBER_NOT_UNIQUE',
@@ -37,6 +38,8 @@ const ERRORS = {
   ENTRIES_ITEMS_IDS_NOT_EXISTS: 'ENTRIES_ITEMS_IDS_NOT_EXISTS',
   NOT_SELLABLE_ITEMS: 'NOT_SELLABLE_ITEMS',
   SALE_INVOICE_NO_NOT_UNIQUE: 'SALE_INVOICE_NO_NOT_UNIQUE',
+  INVOICE_AMOUNT_SMALLER_THAN_PAYMENT_AMOUNT:
+    'INVOICE_AMOUNT_SMALLER_THAN_PAYMENT_AMOUNT',
   INVOICE_HAS_ASSOCIATED_PAYMENT_ENTRIES:
     'INVOICE_HAS_ASSOCIATED_PAYMENT_ENTRIES',
 };
@@ -130,6 +133,20 @@ export default class SaleInvoicesService {
     return entries;
   }
 
+  /**
+   * Validate the invoice amount is bigger than payment amount before edit the invoice.
+   * @param {number} saleInvoiceAmount
+   * @param {number} paymentAmount
+   */
+  validateInvoiceAmountBiggerPaymentAmount(
+    saleInvoiceAmount: number,
+    paymentAmount: number
+  ) {
+    if (saleInvoiceAmount < paymentAmount) {
+      throw new ServiceError(ERRORS.INVOICE_AMOUNT_SMALLER_THAN_PAYMENT_AMOUNT);
+    }
+  }
+
   /**
    * Validate whether sale invoice exists on the storage.
    * @param {Request} req
@@ -267,7 +284,7 @@ export default class SaleInvoicesService {
     saleInvoiceDTO: any,
     authorizedUser: ISystemUser
   ): Promise<ISaleInvoice> {
-    const { SaleInvoice } = this.tenancy.models(tenantId);
+    const { saleInvoiceRepository } = this.tenancy.repositories(tenantId);
 
     const oldSaleInvoice = await this.getInvoiceOrThrowError(
       tenantId,
@@ -309,12 +326,16 @@ export default class SaleInvoicesService {
       'SaleInvoice',
       saleInvoiceDTO.entries
     );
+    // Validate the invoice amount is not smaller than the invoice payment amount.
+    this.validateInvoiceAmountBiggerPaymentAmount(
+      saleInvoiceObj.balance,
+      oldSaleInvoice.paymentAmount
+    );
+
     this.logger.info('[sale_invoice] trying to update sale invoice.');
-    const saleInvoice: ISaleInvoice = await SaleInvoice.query().upsertGraphAndFetch(
-      {
-        id: saleInvoiceId,
-        ...saleInvoiceObj,
-      }
+    const saleInvoice: ISaleInvoice = await saleInvoiceRepository.update(
+      { ...omit(saleInvoiceObj, ['paymentAmount']) },
+      { id: saleInvoiceId }
     );
     // Triggers `onSaleInvoiceEdited` event.
     await this.eventDispatcher.dispatch(events.saleInvoice.onEdited, {
@@ -470,6 +491,7 @@ export default class SaleInvoicesService {
     await Promise.all([
       journal.deleteEntries(),
       journal.saveBalance(),
+      journal.saveContactsBalance(),
       journal.saveEntries(),
     ]);
   }
diff --git a/server/src/subscribers/Bills/SyncVendorsBalances.ts b/server/src/subscribers/Bills/SyncVendorsBalances.ts
deleted file mode 100644
index 020e3bde7..000000000
--- a/server/src/subscribers/Bills/SyncVendorsBalances.ts
+++ /dev/null
@@ -1,68 +0,0 @@
-import { Container } from 'typedi';
-import { EventSubscriber, On } from 'event-dispatch';
-import events from 'subscribers/events';
-import TenancyService from 'services/Tenancy/TenancyService';
-
-@EventSubscriber()
-export default class BillSubscriber {
-  tenancy: TenancyService;
-  logger: any;
-
-  /**
-   * Constructor method.
-   */
-  constructor() {
-    this.tenancy = Container.get(TenancyService);
-    this.logger = Container.get('logger');
-  }
-
-  /**
-   * Handles vendor balance increment once bill created.
-   */
-  @On(events.bill.onCreated)
-  async handleVendorBalanceIncrement({ tenantId, billId, bill }) {
-    const { vendorRepository } = this.tenancy.repositories(tenantId);
-
-    // Increments vendor balance.
-    this.logger.info('[bill] trying to increment vendor balance.', {
-      tenantId,
-      billId,
-    });
-    await vendorRepository.changeBalance(bill.vendorId, bill.amount);
-  }
-
-  /**
-   * Handles vendor balance decrement once bill deleted.
-   */
-  @On(events.bill.onDeleted)
-  async handleVendorBalanceDecrement({ tenantId, billId, oldBill }) {
-    const { vendorRepository } = this.tenancy.repositories(tenantId);
-
-    // Decrements vendor balance.
-    this.logger.info('[bill] trying to decrement vendor balance.', {
-      tenantId,
-      billId,
-    });
-    await vendorRepository.changeBalance(oldBill.vendorId, oldBill.amount * -1);
-  }
-
-  /**
-   * Handles vendor balance difference change.
-   */
-  @On(events.bill.onEdited)
-  async handleVendorBalanceDiffChange({ tenantId, billId, oldBill, bill }) {
-    const { vendorRepository } = this.tenancy.repositories(tenantId);
-
-    // Changes the diff vendor balance between old and new amount.
-    this.logger.info('[bill[ change vendor the different balance.', {
-      tenantId,
-      billId,
-    });
-    await vendorRepository.changeDiffBalance(
-      bill.vendorId,
-      bill.amount,
-      oldBill.amount,
-      oldBill.vendorId
-    );
-  }
-}
diff --git a/server/src/subscribers/SaleInvoices/SyncCustomersBalance.ts b/server/src/subscribers/SaleInvoices/SyncCustomersBalance.ts
deleted file mode 100644
index 015a85ead..000000000
--- a/server/src/subscribers/SaleInvoices/SyncCustomersBalance.ts
+++ /dev/null
@@ -1,81 +0,0 @@
-import { Container } from 'typedi';
-import { On, EventSubscriber } from 'event-dispatch';
-import events from 'subscribers/events';
-import TenancyService from 'services/Tenancy/TenancyService';
-
-@EventSubscriber()
-export default class SaleInvoiceSubscriber {
-  logger: any;
-  tenancy: TenancyService;
-
-  /**
-   * Constructor method.
-   */
-  constructor() {
-    this.logger = Container.get('logger');
-    this.tenancy = Container.get(TenancyService);
-  }
-
-  /**
-   * Handles customer balance increment once sale invoice created.
-   */
-  @On(events.saleInvoice.onCreated)
-  public async handleCustomerBalanceIncrement({
-    tenantId,
-    saleInvoice,
-    saleInvoiceId,
-  }) {
-    const { customerRepository } = this.tenancy.repositories(tenantId);
-
-    this.logger.info('[sale_invoice] trying to increment customer balance.', {
-      tenantId,
-    });
-    await customerRepository.changeBalance(
-      saleInvoice.customerId,
-      saleInvoice.balance
-    );
-  }
-
-  /**
-   * Handles customer balance diff balnace change once sale invoice edited.
-   */
-  @On(events.saleInvoice.onEdited)
-  public async onSaleInvoiceEdited({
-    tenantId,
-    saleInvoice,
-    oldSaleInvoice,
-    saleInvoiceId,
-  }) {
-    const { customerRepository } = this.tenancy.repositories(tenantId);
-
-    this.logger.info('[sale_invoice] trying to change diff customer balance.', {
-      tenantId,
-    });
-    await customerRepository.changeDiffBalance(
-      saleInvoice.customerId,
-      saleInvoice.balance,
-      oldSaleInvoice.balance,
-      oldSaleInvoice.customerId
-    );
-  }
- 
-  /**
-   * Handles customer balance decrement once sale invoice deleted.
-   */
-  @On(events.saleInvoice.onDeleted)
-  public async handleCustomerBalanceDecrement({
-    tenantId,
-    saleInvoiceId,
-    oldSaleInvoice,
-  }) {
-    const { customerRepository } = this.tenancy.repositories(tenantId);
-
-    this.logger.info('[sale_invoice] trying to decrement customer balance.', {
-      tenantId,
-    });
-    await customerRepository.changeBalance(
-      oldSaleInvoice.customerId,
-      oldSaleInvoice.balance * -1
-    );
-  }
-}
diff --git a/server/src/subscribers/paymentMades.ts b/server/src/subscribers/paymentMades.ts
index 32a5fee09..171cf3b95 100644
--- a/server/src/subscribers/paymentMades.ts
+++ b/server/src/subscribers/paymentMades.ts
@@ -21,12 +21,20 @@ export default class PaymentMadesSubscriber {
    */
   @On(events.billPayment.onCreated)
   @On(events.billPayment.onEdited)
-  async handleBillsIncrementPaymentAmount({ tenantId, billPayment, oldBillPayment, billPaymentId }) {
-    this.logger.info('[payment_made] trying to change bills payment amount.', { tenantId, billPaymentId });
+  async handleBillsIncrementPaymentAmount({
+    tenantId,
+    billPayment,
+    oldBillPayment,
+    billPaymentId,
+  }) {
+    this.logger.info('[payment_made] trying to change bills payment amount.', {
+      tenantId,
+      billPaymentId,
+    });
     this.billPaymentsService.saveChangeBillsPaymentAmount(
       tenantId,
       billPayment.entries,
-      oldBillPayment?.entries || null,
+      oldBillPayment?.entries || null
     );
   }
 
@@ -34,51 +42,53 @@ export default class PaymentMadesSubscriber {
    * Handle revert bill payment amount once bill payment deleted.
    */
   @On(events.billPayment.onDeleted)
-  handleBillDecrementPaymentAmount({ tenantId, billPaymentId, oldBillPayment }) {
-    this.logger.info('[payment_made] tring to revert bill payment amount.', { tenantId, billPaymentId });
+  handleBillDecrementPaymentAmount({
+    tenantId,
+    billPaymentId,
+    oldBillPayment,
+  }) {
+    this.logger.info('[payment_made] tring to revert bill payment amount.', {
+      tenantId,
+      billPaymentId,
+    });
     this.billPaymentsService.saveChangeBillsPaymentAmount(
       tenantId,
       oldBillPayment.entries.map((entry) => ({ ...entry, paymentAmount: 0 })),
-      oldBillPayment.entries,
+      oldBillPayment.entries
     );
   }
 
   /**
-   * Handle vendor balance increment once payment made created.
-   */
-  @On(events.billPayment.onCreated)
-  async handleVendorIncrement({ tenantId, billPayment, billPaymentId }) {
-    const { vendorRepository } = this.tenancy.repositories(tenantId);
-
-    // Increment the vendor balance after bills payments.
-    this.logger.info('[bill_payment] trying to increment vendor balance.', { tenantId });
-    await vendorRepository.changeBalance(
-      billPayment.vendorId,
-      billPayment.amount * -1,
-    );
-  }
-
-  /**
-   * Handle bill payment writing journal entries once created. 
+   * Handle bill payment writing journal entries once created.
    */
   @On(events.billPayment.onCreated)
   async handleWriteJournalEntries({ tenantId, billPayment }) {
     // Records the journal transactions after bills payment
     // and change diff acoount balance.
-    this.logger.info('[bill_payment] trying to write journal entries.', { tenantId, billPaymentId: billPayment.id });
+    this.logger.info('[bill_payment] trying to write journal entries.', {
+      tenantId,
+      billPaymentId: billPayment.id,
+    });
     await this.billPaymentsService.recordJournalEntries(tenantId, billPayment);
   }
 
   /**
-   * Decrements the vendor balance once bill payment deleted. 
+   * Handle bill payment re-writing journal entries once the payment transaction be edited.
    */
-  @On(events.billPayment.onDeleted)
-  async handleVendorDecrement({ tenantId, paymentMadeId, oldPaymentMade }) {
-    const { vendorRepository } = this.tenancy.repositories(tenantId);
-
-    await vendorRepository.changeBalance(
-      oldPaymentMade.vendorId,
-      oldPaymentMade.amount,
+  @On(events.billPayment.onEdited)
+  async handleRewriteJournalEntriesOncePaymentEdited({
+    tenantId,
+    billPayment,
+  }) {
+    // Records the journal transactions after bills payment be edited.
+    this.logger.info('[bill_payment] trying to rewrite journal entries.', {
+      tenantId,
+      billPaymentId: billPayment.id,
+    });
+    await this.billPaymentsService.recordJournalEntries(
+      tenantId,
+      billPayment,
+      true
     );
   }
 
@@ -88,24 +98,8 @@ export default class PaymentMadesSubscriber {
   @On(events.billPayment.onDeleted)
   async handleRevertJournalEntries({ tenantId, billPaymentId }) {
     await this.billPaymentsService.revertJournalEntries(
-      tenantId, billPaymentId,
+      tenantId,
+      billPaymentId
     );
   }
-
-  /**
-   * Change the vendor balance different between old and new once
-   * bill payment edited.
-   */
-  @On(events.billPayment.onEdited)
-  async handleVendorChangeDiffBalance({ tenantId, paymentMadeId, billPayment, oldBillPayment }) {
-    const { vendorRepository } = this.tenancy.repositories(tenantId);
-
-    // Change the different vendor balance between the new and old one.
-    await vendorRepository.changeDiffBalance(
-      billPayment.vendorId,
-      oldBillPayment.vendorId,
-      billPayment.amount * -1,
-      oldBillPayment.amount * -1,
-    );
-  }
-}
\ No newline at end of file
+}
diff --git a/server/src/subscribers/paymentReceives.ts b/server/src/subscribers/paymentReceives.ts
index 9d34df629..e975dbd39 100644
--- a/server/src/subscribers/paymentReceives.ts
+++ b/server/src/subscribers/paymentReceives.ts
@@ -39,61 +39,6 @@ export default class PaymentReceivesSubscriber {
     );
   }
 
-  /**
-   * Handle customer balance decrement once payment receive created.
-   */
-  @On(events.paymentReceive.onCreated)
-  async handleCustomerBalanceDecrement({
-    tenantId,
-    paymentReceiveId,
-    paymentReceive,
-  }) {
-    const { customerRepository } = this.tenancy.repositories(tenantId);
-
-    this.logger.info('[payment_receive] trying to decrement customer balance.');
-    await customerRepository.changeBalance(
-      paymentReceive.customerId,
-      paymentReceive.amount * -1
-    );
-  }
-
-  /**
-   * Handle customer balance increment once payment receive deleted.
-   */
-  @On(events.paymentReceive.onDeleted)
-  async handleCustomerBalanceIncrement({
-    tenantId,
-    paymentReceiveId,
-    oldPaymentReceive,
-  }) {
-    const { customerRepository } = this.tenancy.repositories(tenantId);
-
-    this.logger.info('[payment_receive] trying to increment customer balance.');
-    await customerRepository.changeBalance(
-      oldPaymentReceive.customerId,
-      oldPaymentReceive.amount
-    );
-  }
-
-  /**
-   * Handles customer balance diff balance change once payment receive edited.
-   */
-  @On(events.paymentReceive.onEdited)
-  async handleCustomerBalanceDiffChange({
-    tenantId,
-    paymentReceiveId,
-    paymentReceive,
-    oldPaymentReceive,
-  }) {
-    const { customerRepository } = this.tenancy.repositories(tenantId);
-
-    await customerRepository.changeDiffBalance(
-      paymentReceive.customerId,
-      paymentReceive.amount * -1,
-      oldPaymentReceive.amount * -1,
-    );
-  }
-
   /**
    * Handle journal entries writing once the payment receive edited.
    */